Synergistic improvement of flavor development in fermented chili paste through microbial co-fermentation and enzymatic hydrolysis.

This study evaluated eight fermentation strategies to improve flavor development in fermented chili paste. LAB-yeast co-fermentation with Lactiplantibacillus plantarum LP06 and Zygosaccharomyces rouxii ZR26 increased total acidity and amino acid nitrogen, reduced residual sugar and capsaicinoids, enhanced sourness, and decreased bitterness. Cellulase and flavourzyme supplementation promoted substrate conversion and modified taste responses. Untargeted metabolomics showed that co-fermentation without enzyme (LZ) was mainly associated with amino acid- and sulfur-related metabolites, whereas enzyme-assisted co-fermentation (ELZ) modulated lipid- and plant-derived aromatic metabolites. GC-MS identified 166 volatile compounds, including 19 with relative odor activity values >1. LZ showed the highest total VOC content and largest number of potential aroma-active compounds, while ELZ showed higher rOAVs of certain aldehydes, alcohols, sulfur-containing compounds, and terpenoids. Sensory evaluation showed that LZ and ELZ received the highest total sensory scores. Overall, LAB-yeast co-fermentation improved taste and aroma development, while enzymatic hydrolysis modulated metabolite and aroma profiles.